Venomous Household Spiders
Yellow Sac Spider (left) and Hobo Spider
View more spider images at bugguide.net
Yellow sac and hobo spiders are both venomous spiders which often enter homes throughout the US. "Venomous" is an alarming word, but bites occurring from these spiders typically do not lead to serious health problems. With that said, if you have been bitten by a spider or suspect that you have been bitten, you should always seek the advice of a doctor to diagnose the bite and to learn ways to prevent an infection. Yellow sac spiders are found only in the Eastern US in most New England and Midwest states such as Rhode Island, Ohio and Massachusetts. Hobo spiders are only found in the Pacific Northwest in Washington, Idaho and Oregon.
Yellow Sac Spiders
Yellow sac spiders are unique in that they do not build webs. Instead, they create tiny sacs in which they stay during the day. They also create tiny egg sacs which can be seen in corners, behind furniture, on ceilings and in basements. Yellow sac spiders live outside for most of the year but wander into homes as the temperatures drop in the fall. They are small spiders, about 1/4 inch long and pale yellow-green in color. Like most spiders, they come out in the dark and feed on other insects. They will only bite as a defense mechanism when they feel threatened, which can happen as a result of simple contact with humans (like if you put on a shoe that has a spider inside). They are nocturnal, and these spiders occasionally make their way into most areas of the home, including along couches and occasionally even crawl onto people.
The best way to control a yellow sac spider problem is to destroy and remove all sacs in your home. If you have a large-scale problem, then consult with an exterminator who can professionally treat your home. You can also take some preventative steps to keep yellow sac spiders away from your home including: limiting heavy ground-covering vegetation close to your home; sealing cracks and holes around the outside of your home; making sure the the screens on your attic and foundation vents are tight-fitting; and sealing around all plumbing pipes throughout the home.
Hobo Spiders
Hobo spiders are larger than yellow sac spiders and have a long leg span of about an inch and a half. They build flat webs in a funnel shape in holes throughout residential structures. Webs are most commonly seen in holes and cracks in basements, crawlspaces, garages and even in outdoor vegetation. In case you are bitten by a hobo spider, as with all venomous spider bites, you should seek immediate medical attention. It is also important to try to catch the spider that bit you, as it will help in identifying it and determining the proper way to treat the bite. Hobo spiders will only bite upon accidental contact with humans as a defense mechanism.
You can prevent bites and control hobo spiders by removing webs and applying treatments to the cracks. If you have anything more than a minor hobo spider problem, seek the advice of a professional exterminator to find the best way to exterminate.
To prevent hobo spider bites: Shake clothes and shoes before putting them on, remove bed skirts and covers and any other linens that might touch the floor and enable spiders to crawl onto the bed. Move beds away from walls and curtains, keep clothing off of the floor and store shoes in boxes with tight-fitting lids. Additional steps, as mentioned above, can be taken to prevent spiders, including sealing cracks around the home and installing tight attic screens.
Visit Hobospider.org for additional Hobo Spider information.
